1. Technical Field
The present invention relates to an inflatable air bag having an inner bag that defines an inflation fluid volume inside an outer bag.
2. Description Of The Prior Art
U.S. Pat. No. 5,249,824 discloses an air bag including an expansible inner bag that is located in an internal fluid cavity of an outer bag. The inner and outer bags are sewn to each other at the mouth portion of the air bag, surrounding the inflation fluid opening. The inner bag has a plurality of vent openings for directing inflation fluid from the inner bag into the internal cavity of the outer bag in a direction away from the occupant impact area.
The present invention is a vehicle air bag comprising an outer bag having an inflation fluid volume and being inflatable to a predetermined configuration when inflation fluid is directed into the outer bag. The outer bag has a retainer portion defining a central opening. The retainer portion of the outer bag has a plurality of fastener openings spaced apart around the central opening of the retainer portion.
An inner bag is located in the inflation fluid volume of the outer bag and is inflatable to a predetermined configuration within the inflation fluid volume when inflation fluid is directed into the inner bag. The inner bag has a retainer portion defining an inflation fluid opening for receiving inflation fluid. The retainer portion of the inner bag has a plurality of fastener openings spaced apart around the inflation fluid opening of the retainer portion of the inner bag. The inner bag has at least one vent opening movable from a closed condition to an open condition, in response to increase in fluid pressure in the inner bag, to enable flow of inflation fluid from the inner bag into the inflation fluid volume of the outer bag.
The air bag assembly further comprises a plurality of fasteners extending through the fastener openings in the retainer portion of the outer bag and through the fastener openings in the retainer portion of the inner bag to secure the inner bag to the outer bag without sewing. The retainer portion of the outer bag is free of stitching openings.